GRIN lens and lens array fabrication with diffusion-driven photopolymer.

We introduce a new method to make gradient index (GRIN) lenses and GRIN lens arrays by exposing diffusion-driven photopolymers using a low-power CW laser. By changing the size and power of the laser beam and the exposure time the index profile of the GRIN lens can be controlled. Combined with the self-developing nature of the photopolymer, this enables rapid "on-demand" printing of arbitrary micro-optics. We also introduce a new form of scanning phase microscopy that is conveniently integrated into the lens exposure hardware, providing accurate process monitoring.